Static routing design considerations

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Static routing design considerations

To prevent problems, you should consider the following design issues before you implement static routing.

Peripheral router configuration

To simplify configuration, you can configure peripheral routers with a default route that points to the neighboring router. A peripheral router is a router attached to multiple networks, only one of which has a neighboring router.

Default routes and routing loops

It is recommended that you do not configure two neighboring routers with default routes that are pointing to each other. A default route passes all traffic that is not on a directly connected network to the configured router. Two routers that have default routes pointing to each other may produce routing loops for traffic with an unreachable destination.

Demand-dial environments

You can implement static routing across demand-dial links in one of two ways:

• Default route

  You can configure a default route on the branch office router that uses the demand-dial interface. The advantage of a default route is that a single route only needs to be added once. The disadvantage of a default route is that any traffic, including traffic for unreachable destinations, that is not on the branch office network causes the branch office router to call the main office.

• Auto-static routes

  Auto-static routes are static routes that are automatically added to the routing table for a router after routes are requested across a demand-dial connection by using the RIP-for-IP routing protocol. The advantage of auto-static routes is that unreachable destinations do not cause the router to call the main office. The disadvantage of auto-static routes is that they must be periodically updated to reflect the networks that are reachable at the main office. If a new network is added to the main office and the branch office has not performed an auto-static update, all destinations on the new main office network are unreachable from the branch office.